I have the chess.com app for my HTC Thunderbolt and for me it seems to have quite a few problems.

Even when I quit the application randomly pops back to the last played game and makes a sound. Nothing seems to fix this, I tried to unload it from memory manually and got an error. Manually rebooting the device after using the application is cumbersome.

Also for some reason the screen brightness settings don't seem to apply while inside the app. Only reason I noticed this is because, as many htc thunderbolt owners are aware, the battery life is miserable with the screen brightness up. With the standard battery I'd say my phone lasts 2-3 hours tops with the screen brightness on full which seems to be entirely while inside the chess.com app.